Chapter 14 Mastering A&P – Flashcards
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For which of the following activities is the parasympathetic nervous system generally responsible?
fight-or-flight responses
resting and digesting
vigorous physical activity
sweating and dilating pupils
answer
resting and digesting
rationale: The parasympathetic division, sometimes called the "rest and digest" system, keeps body energy use as low as possible, even as it directs vital "housekeeping" activities like digesting food and eliminating feces and urine.
question
Which of the following is NOT associated with the parasympathetic division of the autonomic nervous system (ANS)?
emergency action
resting
energy conservation
digesting
answer
emergency action
rationale: The activity of the sympathetic division, often called the "fight-or-flight" system, is evident when we are excited, exercising, or find ourselves in emergency situations.
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What differentiates an autonomic reflex from a somatic reflex?
a single sensory neuron in the sensory pathway
a two-neuron motor pathway
an integration center
presence of a sensory receptor
answer
a two-neuron motor pathway
rationale: Visceral reflex arcs have essentially the same components as somatic reflex arcs - receptor, sensory neuron, integration center, motor neuron, and effector. A key difference is that a visceral reflex arc has two neurons in its (autonomic) motor component, whereas the somatic reflex arc has a single (somatic) motor neuron.
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Which of the following best demonstrates an example of cooperation of the parasympathetic and sympathetic nervous systems?
Parasympathetic stimulation causes vasodilation of blood vessels in the penis, leading to erection; sympathetic stimulation then causes ejaculation.
Sympathetic stimulation causes vasodilation of blood vessels in the penis, leading to erection; parasympathetic stimulation then causes ejaculation.
Parasympathetic stimulation causes copious sweating; sympathetic stimulation causes epidermal pores to dilate.
Sympathetic stimulation causes vasodilation of blood vessels in the clitoris, leading to erection; parasympathetic stimulation then causes reflex contractions of the vagina.
answer
Parasympathetic stimulation causes vasodilation of blood vessels in the penis, leading to erection; sympathetic stimulation then causes ejaculation.
rationale: The best example of cooperative autonomic effects is seen in controls of the external genitalia. Parasympathetic stimulation causes vasodilation of blood vessels in the external genitalia, and is responsible for erection of the male penis or female clitoris during sexual excitement. Sympathetic stimulation then causes the ejaculation of semen by the penis or reflex contractions of the vagina during an orgasm.
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Which of the following is responsible for the overall integration of the autonomic nervous system (ANS)?
frontal lobe of the cerebral cortex
reticular formation
brain stem
hypothalamus
answer
hypothalamus
rationale: The hypothalamus stands at the top of the control hierarchy as the integrator of ANS activity.
question
The sympathetic and parasympathetic divisions of the ANS have the same effect on most body organ systems.
True
False
answer
False
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The ANS stimulates smooth muscles, skeletal muscles and glands, whereas the somatic nervous system innervates skeletal muscles only.
True
False
answer
False
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Sympathetic division stimulation causes ________.
increased blood glucose, increased GI peristalsis, and decreased heart rate and blood pressure
increased blood glucose, decreased GI peristalsis, and increased heart rate and blood pressure
decreased blood glucose, increased GI peristalsis, and decreased heart rate and blood pressure
decreased blood glucose, increased GI peristalsis, and increased heart rate and blood pressure
answer
increased blood glucose, decreased GI peristalsis, and increased heart rate and blood pressure
question
Which of the following does not describe the ANS?
general visceral motor system
involuntary nervous system
a system of motor neurons that innervates smooth and cardiac muscle and glands
a system of motor neurons that innervates all muscle cells
answer
a system of motor neurons that innervates all muscle cells
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Which organ receives major input from the sympathetic, but not parasympathetic, division?
heart
salivary glands
bladder
skin
answer
skin
rationale: The smooth muscle of dermal blood vessels and arrector pili are innervated by the sympathetic, but not parasympathetic, division.
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Blood "shunting" is a dangerous situation in which the vital organs shut down, causing the body to go into circulatory shock.
True
False
answer
False
During circulatory shock (inadequate blood flow to body tissues), or when more blood is needed to meet the increased demands of working skeletal muscles, blood vessels serving the skin and abdominal viscera strongly constrict. This blood "shunting" helps maintain circulation to vital organs and skeletal muscles.
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Preparing the body for the "fight-or-flight" response is the role of the ________.
cerebrum
parasympathetic nervous system
sympathetic nervous system
somatic nervous system
answer
sympathetic nervous system
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The ANS contains both sensory and motor neurons..
True
False
answer
False
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Conduction through the autonomic efferent chain is faster than conduction in the somatic motor system.
True
False
answer
False
rationale: Preganglionic axons are thin, lightly myelinated fibers, and postganglionic axons are even thinner and nonmyelinated. Consequently, conduction through the autonomic efferent chain is slower than conduction in the somatic motor system (which uses thick, heavily myelinated fibers).
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The craniosacral division is another name for the parasympathetic division.
The craniosacral division is another name for the parasympathetic division.
True
False
answer
True
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Which division of the nervous system has short preganglionic neurons?
somatic sensory
somatic motor
sympathetic
parasympathetic
answer
sympathetic
rationale: The sympathetic division has short preganglionic fibers and long postganglionic fibers. The parasympathetic division has long preganglionic fibers and short postganglionic fibers. The somatic division has a single lower motor fiber (no preganglionic or postganglionic fibers).
question
Control of temperature, endocrine activity, and thirst are functions associated with the ________.
medulla
hypothalamus
thalamus
cerebellum
answer
hypothalamus
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The two divisions of the autonomic nervous system (ANS) normally have a(n) __________ relationship.
antagonistic
disruptive
synergistic
mutualistic
answer
antagonistic
rationale: Normally, both ANS divisions are partially active. Action potentials continually fire down both sympathetic and parasympathetic axons, producing a dynamic antagonism that precisely controls visceral activity. However, one division usually predominates in given circumstances, producing an effect that is countered by the other division (resulting in opposite actions at the target organ). In a few cases the two divisions actually cooperate with each other.
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The "resting and digesting" division of the autonomic nervous system is the ________.
somatic division
peripheral nervous system
sympathetic division
parasympathetic division
answer
parasympathetic division
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Which of the following is NOT an autonomic nervous system (ANS) effector?
skeletal muscle
cardiac muscle
smooth muscle
glands
answer
skeletal muscle
rationale: the somatic nervous system stimulates skeletal muscle, whereas the ANS innervates cardiac muscle, smooth muscle, and glands.
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Because the ANS is a visceral motor system, afferent pathways are of no importance and actually are rarely found.
True
False
answer
false
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Acetylcholine is the substance released by the axonal endings of the somatic efferent fibers and by the parasympathetic nerve fiber endings.
True
False
answer
true
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The autonomic nervous system may cause activation or inhibition, depending on the division that is active and the target that is affected.
True
False
answer
true
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The sympathetic division is also called the "thoracolumbar division" of the autonomic nervous system.
True
False
answer
true
rationale: The sympathetic division is also called the "thoracolumbar division" of the autonomic nervous system because the thoracic and upper lumbar spinal segments (T1 through L2) contain the cell bodies of all preganglionic sympathetic neurons.
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Which component of the ANS is characterized by ganglia located in or near effector organs?
sympathetic division
somatic division
parasympathetic division
answer
parasympathetic
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A synonym for the autonomic nervous system reflects its major function. The synonym is _________.
the peripheral nervous system
the central nervous system
the involuntary nervous system
the somatic nervous system
answer
the involuntary nervous system
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preganglionic axons are ________.
heavily myelinated
lightly myelinated
nonmyelinated
lightly myelinated and nonmyelinated
answer
lightly myelinated
question
How is it possible that norepinephrine can cause vasoconstriction in one location but vasodilation in another?
Sometimes norepinephrine is released by the parasympathetic nervous system, which causes relaxation.
Receptor types differ in these tissues.
Norepinephrine is not released by the
parasympathetic nervous system.
It can't: Its actions are predictable no matter the tissue.
answer
Receptor types differ in these tissues.
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In general, sympathetic innervation of visceral organs inhibits the activity of these organs. This is logical because,
sympathetic input primes the body to enter a resting state
sympathetic input is always inhibitory
parasympathetic innervation is lacking from this area
sympathetic activity primes the body for physical activity and temporarily shuts down noncritical body activities
answer
sympathetic activity primes the body for physical activity and temporarily shuts down noncritical body activities
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the parasympathetic nervous system is more active when we are ______.
at rest
digesting food
exercising
both a and b
answer
both a and b
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Which of the following statements is true of the parasympathetic nervous system?
The preganglionic fibers are shorter than the postganglionic fibers.
The fibers emerge from the brain and sacral portion of the spinal cord.
The ganglia lie close to the spinal cord.
All of the above statements are true.
answer
The fibers emerge from the brain and sacral portion of the spinal cord.
question
Which of the following sets of conditions accurately describes the anatomy of the parasympathetic nervous system?
• Thoracolumbar origin; long preganglionic fibers; ganglia in visceral effector organs
• Craniosacral origin; short preganglionic fibers; ganglia in visceral effector organs
• Craniosacral origin; long preganglionic fibers; ganglia in visceral effector organs
• Thoracolumbar origin; short preganglionic fibers; ganglia close to the spinal cord
answer
Craniosacral origin; long preganglionic fibers; ganglia in visceral effector organs
